CN107145184A - A kind of temperature compensation of variable power reference source - Google Patents

Abstract

The present invention proposes a temperature compensation method for a variable power reference source. First, in a normal temperature environment, use a computer to perform linear compensation at normal temperature on the reference source of the power meter to be compensated; The DAC deviation value and temperature detection ADC value; then, get the DAC deviation value and temperature detection ADC value of all reference sources to be compensated at 10°C, 40°C, and 50°C; then, the DAC value and power value at normal temperature The corresponding table is corrected to obtain the DAC correction table of 0°C, 10°C, 40°C, and 50°C; in normal operation, the power meter reads the reference source temperature to detect the ADC value at a fixed interval, and detects the temperature of the ADC value according to the temperature Range and adjacent DAC correction table, use linear interpolation algorithm to get a table corresponding to the current DAC and power value, and set the DAC value of the reference source according to the table when calibrating the power sensor.

Description

A Method of Temperature Compensation for Variable Power Reference Source

technical field

The invention relates to the technical field of testing, in particular to a temperature compensation method for a variable power reference source.

Background technique

There is a detection diode in the variable power reference source circuit. At different temperatures, the detection diode is more sensitive to the influence of temperature. In order to eliminate the influence of temperature on the detection diode, it is necessary to perform temperature compensation on the variable power reference source circuit.

As shown in Figure 1, the variable power reference source circuit includes: signal generation unit A1, which generates a continuous wave signal with a frequency of 1 GHz, which is amplified by the first-stage amplifier A2 to amplify the power above +13dBm; power modulator A3 , which adjusts its own output power according to the output voltage of the amplitude modulation generator A13; the second-stage amplifier A4 performs power amplification on the output signal of the power modulator A3, and its maximum power output is greater than +25dBm; the directional coupler A5, its main output to the attenuation network A6, and then output to the panel of the power meter through the port matching network A7, the coupling end of the directional coupler A5 outputs to the detector A11, and the detector A11 is composed of a detector diode D1 and a detector capacitor C1, and R1 is The detector output adjustment resistor; 16-bit DACA12, R2 is the DAC output adjustment resistor; the output voltage of the detector A11 acts on the amplitude modulation generator A13 through its output adjustment resistor R1, and the DAC A12 output voltage through its output adjustment resistor R2. The modulation generator A13 generates the voltage to control the power modulator A3 according to the output voltage of the detector A11 and DAC A12, thereby controlling the power output of the reference source; the temperature sensor A8 is located near the detector A11; the temperature detection ADC A9 is used to detect the temperature Voltage value of sensor A8.

Since the detection diode D1 is a temperature-sensitive device, when the temperature changes, the voltage value of the output terminal Vt of the detection diode D1 changes, and the voltage at the back end of the amplitude modulation generator A13 changes, which affects the power modulator A3, thereby affecting the reference source power output.

The existing technical solution is: build a reference source temperature compensation system with a computer, a standard power meter and a power meter to be compensated, put the power meter in a constant temperature box, connect the power probe of the standard power meter to the output of the reference source, and use The computer program controls the standard power meter and the power meter to be compensated, and compensates the reference source of the power meter to be compensated at different temperatures.

The existing reference source compensation method needs to collect and compensate data in steps of 1dB at the temperature points of 0°C, 10°C, 40°C and 50°C, and automatically collect data through the computer. Only one power reference can be compensated at a time. source, it takes about 5 hours, and the compensation efficiency is low.

Contents of the invention

The invention proposes a temperature compensation method for a variable power reference source, which solves the problem of low temperature compensation efficiency of the power reference source in the prior art.

Technical scheme of the present invention is realized like this:

A temperature compensation method for a variable power reference source, using a computer, a standard power meter, and a power meter to be compensated to construct a compensation system, including the following steps:

First, under normal temperature environment, use the computer to perform linear compensation at normal temperature on the reference source of the power meter to be compensated, obtain the corresponding table of DAC value and power value at normal temperature, and save the temperature detection ADC value corresponding to each power point;

Next, get the DAC deviation value and temperature detection ADC value of all power meters to be compensated at 0°C;

Then, obtain the DAC deviation value and temperature detection ADC value of all the reference sources to be compensated at the target temperature;

Then, according to the DAC deviation value and temperature detection ADC value of all the reference sources to be compensated at 0°C and the target temperature, the corresponding table of the DAC value and the power value at normal temperature is corrected to obtain the DAC correction of 0°C and the target temperature sheet;

During normal operation, the power meter reads the reference source temperature detection ADC value at regular intervals. According to the temperature range of the temperature detection ADC value and the adjacent DAC correction table, a linear interpolation algorithm is used to obtain a table corresponding to the current DAC and power value. , when calibrating the power sensor, set the DAC value of the reference source according to this table.

Optionally, the above-mentioned temperature compensation method for a variable power reference source specifically includes the following steps:

Step 1: In a normal temperature environment, use a computer to perform linear compensation at normal temperature on the reference source of the power meter to be compensated, establish the corresponding relationship between -40dBm~+20dBm at normal temperature, and the DAC of the whole point power, and record the temperature detection ADC at normal temperature at the same time value; set the reference source step of the power meter to be compensated, the DAC correspondence of the non-integer power point is obtained by the interpolation of the whole point power DAC, and the corresponding table between the DAC value and the power value at room temperature is obtained, and the temperature detection corresponding to each power point is saved ADC value;

Step 2: Set the temperature of the temperature box to 0°C, wait until the temperature drops to 0°C, and keep it for a period of time to stabilize the temperature of the power meter to be compensated;

Step 3: Connect the standard power probe to the reference source output terminal of the standard power meter, perform calibration operation, then connect the standard power probe to the half-steel cable, and connect the other end of the half-steel cable to the first power meter to be compensated Reference source output terminal for zero calibration operation;

Step 4. Open the temperature compensation panel of the reference source of the first power meter to be compensated. First, select the +20dBm menu and adjust the coefficient on the menu so that the degree in the standard power meter is +20dBm±0.004dB; then, adjust +10dBm in turn , 0dBm, -10dBm, -30dBm output, so that the deviation of the measured value of the standard power meter is within ±0.004dB; then, the DAC deviation value and temperature detection ADC value of the first power meter reference source to be compensated at 0°C, Save to the first power meter to be compensated;

Step 5, connect the semi-steel cable to the reference source output terminal of the second power meter to be compensated, and repeat step 4 to obtain the deviation value of the reference source of the second power meter to be compensated at 0°C and the temperature detection ADC value, and save it to the second Two power meters to be compensated; connect the semi-steel cables to the reference source output terminals of other power meters to be compensated in turn, and obtain the DAC deviation value and temperature detection ADC value of all power meters to be compensated at 0°C;

Step 6: Set the temperature box to 10°C, 40°C, and 50°C in turn, wait until the temperature reaches the set value, keep it for a period of time, repeat steps 4 to 5, and get all reference sources to be compensated at 10°C, 40°C , DAC deviation value and temperature detection ADC value at 50°C;

Step 7, according to the obtained temperature detection ADC value of each temperature point and the DAC deviation value of +20dBm, +10dBm, 0dBm, -10dBm, -30dBm power point, the corresponding table of DAC value and power value at normal temperature is corrected to obtain DAC correction table for 0°C, 10°C, 40°C, 50°C;

Step 8: In normal operation, the power meter reads the reference source temperature detection ADC value at regular intervals, and according to the temperature range of the temperature detection ADC value and the nearby DAC correction table, uses a linear interpolation algorithm to obtain a current DAC and power value The corresponding table, when calibrating the power sensor, set the DAC value of the reference source according to the table.

Optionally, in the step 1, the reference source setting step is 0.1dB, and the DAC correspondence of the non-integer power point is obtained by interpolation of the whole point power DAC, and the corresponding table DAC of the _DAC value and the power value at room temperature is obtained. _(ADC) [601], this table takes 0.1dB as a step, saves the temperature detection ADC value corresponding to each power point.

The beneficial effects of the present invention are:

(1) According to the above-mentioned temperature compensation method of the present invention, at least 12 reference sources can be compensated once in a temperature box of 1 cubic meter, and the time spent is about 6.5 hours, and the efficiency is improved by about 10 times compared with the current method, and the efficiency is high;

(2) The compensation can be completed by simply setting a few parameters manually, and the operation is simple.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention. Those skilled in the art can also obtain other drawings based on these drawings without creative work.

Fig. 1 is the circuit diagram of variable power reference source circuit;

Fig. 2 is the control block diagram of temperature compensation system of the present invention;

FIG. 3 is a schematic diagram of a reference source temperature compensation panel of the present invention.

detailed description

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

The principle of temperature compensation of the reference source by the temperature compensation method of the present invention is: at different temperatures, adjust the output of the DAC A12 in FIG. 1 to compensate the change of Vt caused by the temperature change of the detector A11, thereby ensuring the output power of the reference source is accurate.

As shown in Figure 2, the temperature compensation method of the present invention is based on a temperature compensation system, the temperature compensation system includes: a temperature box N1 that can set the temperature, and the power meters N2(1)-N2(n) to be compensated are placed in the temperature box In N1, when the volume of temperature box N1 is 1 cubic meter, at least 12 power meters to be compensated can be placed at the same time; standard power meter N3, standard power probe N4, cable L1 connects standard power meter N3 and standard power probe N4, half steel One end of the cable L2 is connected to the reference source of the power meter to be compensated, and the other end is connected to the standard power probe N4. The standard power probe N4 should be placed outside the temperature box. The length of the half-steel cable L2 is 0.5m.

The temperature compensation process of the temperature compensation method of the present invention is specifically as follows:

Step 1: Under normal temperature (20°C-25°C), use a computer, a standard power meter, and a power meter to be compensated to build a temperature compensation system. Each power meter to be compensated has a temperature sensor and a temperature ADC converter. After warming up for 30 minutes, use the computer program to perform linear compensation at normal temperature on the reference source of the power meter to be compensated, and establish the corresponding relationship between -40dBm～+20dBm and DAC at the whole point power at normal temperature, such as DAC ₊ 20dbm, DAC _+19dbm ......DAC _-40dbm , and record the temperature detection ADC value at room temperature at the same time.

The above reference source of the power meter to be compensated is set at a step of 0.1dB, and the DAC correspondence of the non-integer power point is obtained by the interpolation of the whole point power DAC, and the corresponding table of DAC value and power value at room temperature is obtained

DAC _{normal temperature (ADC)} [601], the table takes 0.1dB as a step and saves the ADC value corresponding to each power point.

Step 2: Set the temperature of the temperature box N1 to 0°C, wait for the temperature to drop to 0°C, and keep it for 30 minutes to allow the temperature of the power meter to be compensated to stabilize.

Step 3, set the resolution of the standard power sensor N4 to display to 3 decimal places. Connect the standard power probe N4 to the reference source output terminal of the standard power meter N3, perform "calibration" operation, then connect the standard power probe N4 to the semi-steel cable L2, and connect the other end of the semi-steel cable L2 to the first standby Compensate the reference source of the power meter N2(1), and perform the "zero calibration" operation.

Step 4, open the reference source temperature compensation panel of the first power meter to be compensated N2(1), as shown in Figure 3, K1 ~ K6 are the buttons on the power meter panel, first press K1, select the +20dBm menu, and pass through the power meter panel Adjust the coefficient on the menu so that the degree in the standard power meter N4 is +20dBm±0.004dB. Then press K1 ~ K5 in turn to adjust the output of +10dBm, 0dBm, -10dBm, -30dBm, so that the deviation of the measured value of the standard power meter is within ±0.004dB. Press K6 to save the DAC deviation ΔDAC ₊₂₀ ~ ΔDAC _-30 of the reference source of the first power meter to be compensated N2(1) at 0°C and the temperature ADC value 0°C (ADC) to the first power meter to be compensated.

Step 5, connect the semi-steel cable L2 to the reference source output of the second power meter to be compensated N2(2), repeat step 4, and obtain the deviation value and temperature of the reference source of the second power meter to be compensated N2(2) at 0°C The ADC value is detected and saved to the second power meter to be compensated N2(2). Connect the semi-steel cable L2 to other power meters to be compensated N2(3)~N2(n) in sequence, and obtain the deviation value of the reference source of all power meters to be compensated at 0°C and the temperature detection ADC value.

Step 6: Set the temperature box N1 at 10°C, 40°C, and 50°C in turn. After the temperature reaches the set value, keep it for 30 minutes. , DAC deviation value and temperature detection ADC value at 40°C and 50°C.

Step 7: The power meter to be compensated detects ADC values (0°C (ADC), 10°C (ADC), 40°C (ADC), 50°C (ADC)) and representative power points ( +20dBm, +10dBm, 0dBm, -10dBm, -30dBm) DAC deviation value relative to normal temperature, correct the table DAC _{normal temperature (ADC)} [601] at normal temperature, and get 0℃, 10℃, 40℃, 50℃ DAC correction table for DAC _{0°C (ADC)} [601], DAC _{10°C (ADC)} [601], DAC _{40°C (ADC)} [601], DAC _{50°C (ADC)} [601].

Step 8: During normal operation, power meters N2(1)~N2(n) read their reference source temperature detection ADC value T(ADC) every 1 minute, according to the temperature range of T(ADC) and the adjacent DAC Correct the table, (for example, if the current temperature ADC is between 0°C and 10°C, then according to the table DAC _{0°C (ADC)} [601] and DAC _{10°C (ADC)} [601]), use a linear interpolation algorithm to obtain a current DAC The table DAC _T(ADC) [601] corresponding to the power value, when calibrating the power sensor, set the DAC value of the reference source according to the DAC _T(ADC) [601] table.

According to the above-mentioned temperature compensation method of the present invention, at least 12 reference sources can be compensated at a time in a temperature box of 1 cubic meter, and it takes about 6.5 hours, and the efficiency is increased by about 10 times compared with the current method, and the efficiency is high; The compensation can be completed by setting parameters, and the operation is simple.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the scope of the present invention. within the scope of protection.

Claims (3)

1. a kind of temperature compensation of variable power reference source, is built with computer, reference power meter, power meter to be compensated and mended Repay system, it is characterised in that comprise the following steps：

First, under normal temperature environment, the linear compensation under normal temperature is carried out to power meter reference source to be compensated with computer, is obtained often The lower DAC value of temperature and the corresponding form of performance number, preserve the corresponding temperature detection ADC values of each power points；

Next, obtaining DAC deviation and temperature detection ADC value of all power meters to be compensated at 0 DEG C；

Then, DAC deviation and temperature detection ADC value of all reference sources to be compensated in target temperature are obtained；

Subsequently, the DAC deviations and temperature detection ADC values according to all reference sources to be compensated in 0 DEG C and target temperature, DAC value under normal temperature is modified with the corresponding form of performance number, the DAC correction cards of 0 DEG C and target temperature are obtained；

Power meter reads a secondary reference temperature detection ADC values per fixed intervals, according to temperature detection ADC values in normal work Residing temperature range and the DAC correction cards closed on, using linear interpolation algorithm, obtain a current DAC corresponding with performance number Form, when power probe is calibrated, according to the DAC value of the Tabulator Setting reference source.

2. a kind of temperature compensation of variable power reference source as claimed in claim 1, it is characterised in that specifically include with Lower step：

Step one, under normal temperature environment, the linear compensation under normal temperature is carried out to power meter reference source to be compensated with computer, is set up Under normal temperature between -40dBm~+20dBm, the DAC of integral point power corresponding relation, while recording temperature detection ADC values under normal temperature； Power meter reference source stepping to be compensated is set, and the DAC corresponding relations of non-integer power points are obtained by integral point power DAC by interpolation Arrive, obtain DAC value and the corresponding form of performance number under normal temperature, preserve the corresponding temperature detection ADC values of each power points；

Step 2, design temperature case temperature is 0 DEG C, and a period of time is kept after 0 DEG C when temperature is dropped to, power meter temperature to be compensated is allowed Degree is settled out；

Step 3, calibration power is popped one's head in and is connected to the reference source output terminal of reference power meter, calibration operation is carried out, then by standard Power probe is connected to half steel cable, and by another reference source output terminal for terminating to the first power meter to be compensated of half steel cable, Carry out school Z-operation；

Step 4, opens the temperature-compensating panel of the first power meter reference source to be compensated, first, chooses+20dBm menus, adjusts Coefficient on menu so that the number of degrees in reference power meter are+20dBm ± 0.004dB；Then, be sequentially adjusted in+10dBm, 0dBm, -10dBm, -30dBm output so that reference power meter measured value deviation is within ± 0.004dB；Subsequently, by 0 DEG C When the first power meter reference source to be compensated DAC deviations and temperature detection ADC values, be saved in the first power meter to be compensated；

Step 5, half steel cable is connected to the reference source output terminal of the second power meter to be compensated, and repeat step four obtains second and treated Deviation and temperature detection ADC value of the power meter reference source at 0 DEG C are compensated, and is saved in the second power meter to be compensated；Successively will Half steel cable is connected to other power meters to be compensated and refers to source output terminal, obtains DAC deviation of all power meters to be compensated at 0 DEG C With temperature detection ADC values；

Step 6, is set as 10 DEG C, 40 DEG C, 50 DEG C by sweat box successively, until temperature is reached after setting value, is kept for one section Between, four~step 5 of repeat step obtains DAC deviation and temperature of all reference sources to be compensated at 10 DEG C, 40 DEG C, 50 DEG C Detect ADC values；

Step 7, according to the temperature detection ADC values of each obtained temperature spot and+20dBm ,+10dBm, 0dBm, -10dBm, - 30dBm power points DAC deviations, are modified to the DAC value under normal temperature with the corresponding form of performance number, obtain 0 DEG C, 10 DEG C, 40 DEG C, 50 DEG C of DAC correction cards；

Step 8, power meter is read a secondary reference temperature detection ADC values per fixed intervals, examined according to temperature in normal work Temperature range residing for ADC values and the DAC correction cards closed on are surveyed, using linear interpolation algorithm, current a DAC and power is obtained It is worth corresponding form, when power probe is calibrated, according to the DAC value of the Tabulator Setting reference source.

3. a kind of temperature compensation of variable power reference source as claimed in claim 2, it is characterised in that the step one In, reference source sets stepping to be 0.1dB, and the DAC corresponding relations of non-integer power points are obtained by integral point power DAC by interpolation, Obtain the form DAC corresponding with performance number of DAC value under normal temperature_{Normal temperature (ADC)}[601], the form preserves each work(using 0.1dB as stepping The corresponding temperature detection ADC values of rate point.